Deep fried foods such as french fries and potato chips are quick, appetizing foods. However, deep fried foods have been losing popularity due to the fitness craze and the average consumer's heightened awareness of the fat content of food they ingest. The average french fry having a 9/32".times.9/32" cross section contains about 14-18% fat by weight which causes most fat-conscious consumers to avoid french fries altogether.
When foods are formulated to be low-fat, the low-fat product generally suffers in texture and flavor. The aim of this invention is to produce a reduced fat french fry which does not suffer the deleterious effects generally associated with low-fat foodstuffs.
U.S. Pat. No. 3,397,993 discloses a conventional process for preparing french fries. The process of the '993 patent is diagrammed in FIG. 1. First the potatoes are washed, peeled and cut into elongated strips. The strips are then washed to remove the free starch remaining on the surface. Next the potato strips are blanched in steam (about 2 to 10 minutes at about 200.degree. F. to 212.degree. F.) or water (160.degree. F. to 200.degree. F. for 3 to 8 minutes) until they turn to a generally translucent condition throughout. The strips are then dehydrated to effect a weight loss of from 20-30% by blowing 150.degree. to 350.degree. F. air on the strips for 5 to 20 minutes. Following dehydration, the strips are partially deep fat fried (parfried) for from about 15-60 seconds at a temperature of about 300.degree. F. to about 375.degree. F. After the partial fry, the strips are frozen down to about 0.degree. F. When the frozen product is prepared by the final user, it is finish fried in a suitable oil for about 1.5 to 3 minutes at about 300-375.degree. F.
A common practice in the art is to dip the blanched strips into a 0.5 to 0.75% sodium acid pyrophosphate (SAPP) solution for up to about 5 minutes before dehydrating the strips. The SAPP acts as a color brightener. Dextrose, which acts as a coloring agent, may additionally be added to the solution to help turn the french fries to a golden brown color. This step helps to create a product with a more uniform surface color and may be added or entirely omitted depending on the sugar content of the potato used.
Coatings have been used in the art to create a barrier to limit fat absorption during deep fat frying and to improve the texture of deep-fried potato products. U.S. Pat. No. 3,751,268 discloses coating a potato with a slurry at about 120.degree. F. to 180.degree. F. containing about 6.5% ungelatinized high amylose starch and then frying the potato at about 325.degree. F. to about 380.degree. F. to gelatinize the amylose. The high amylose starch has an amylose content of more than 50% by weight. The '268 patent discloses that using this process results in a french fry having about 10%-20% less oil than conventionally prepared french fries.
Amylose coatings have further been used to improve the crisp texture of deep fried potato products. U.S. Pat. No. 3,597,227 discloses coating a potato with a hot gelatinized aqueous dispersion of amylose. The '227 patent further mentions that a calcium lactate treatment may be completed before coating the potatoes with the hot amylose dispersion to aid in creating a crisp textured french fry.
Calcium has been added to potatoes in producing deep fried potato products to enhance the texture of the resulting french fries and potato chips. U.S. Pat. No. 4,272,554 discloses the use of calcium to inhibit blister formation in potato chips. The '554 patent states that if the amount of calcium added to the potatoes is kept low the potato chips are generally less oily than their blistered counterparts. However, if the amount of calcium raises above about 1000 parts per million based on the weight of the fried chips, oiliness and brittleness of the chips increases. The '554 patent limited the amount of calcium ions in the dip solution to below about 0.2% by weight.
U.S. Pat. No. 4,254,153 lists calcium salts as one of many firming agents which can be used to improve crispness in french fries. However, the '153 patent states that such a calcium salt treatment to improve crispness and rigidity has been successful only to a limited degree and is dependent upon the condition of the raw potato. U.S. Pat. No. 3,424,59 also discloses using calcium lactate as a stiffening agent to improve the physical appearance and plate life of french fries. The '591 patent further disclosed that use of calcium lactate treatment in their process did not reduce oil absorption of the potatoes during frying.